开封县棉花主要分布在黄河大堤以南的背河洼地,土质盐碱,历史上一年一熟,棉花亩产只有二三十公斤。近几年随着生产条件的改变,耕作技术水平的提高,棉田由一年一熟改为麦棉、瓜棉套种两熟。由于棉花苗期受间套作物的影响,加上盐碱危害生长瘦 Kaifeng County cotton is mainly distributed in the back river depression south of the Yellow River embankment, soil salinization, the history of a year a year, only twenty or thirty kilograms of cotton per mu. In recent years, with the change of production conditions and the improvement of farming techniques, the cotton fields are changed from one-year-old to wheat-wool and the two varieties of melon and cotton are inter-planted. Cotton seedling affected by intercropping crops, coupled with salt harm the growth of thin